How do I add a custom Merge Field in the Freeform editor?

To insert a merge field into your email please follow these steps.

1.) Place your mouse cursor where you want the merge field to appear in the HTML code
2.) Click Insert from the drop down menu on the left side of the toolbar
3.) Select the Merge Field that you want to use in your email
4.) Specify a Default Value to appear in case the field is blank

This will insert the merge field when you placed your cursor in the following format: 

{FIRST_NAME|Reader}

The merge field is the content to the left of the | character, the default value is to the right. Your recipient will see the data that appears in your list for the specified field but if the data in your list is missing the recipient will see the default value.